Kitchen sink needs dumps into cabinet

[JewishBacon]

I feel like something is wrong with my plumbing. I get water gushing out of this vent ALL THE TIME when the water level in the sink backs up because of small food bits clogging the sink we have a septic tank and therefore no disposal. Is there anything I can do about this?

It drives me absolutely crazy. We don't dump large food scraps after I scrape plates into the trash there might be a few grains of rice or something that make it down the drain but that's it.

 

[Geofd]

try removing the vent ….run some water and see what happens

 

[Diehard]

It sounds like you may have a partial clog/slow-down of flow downstream of the vent, causing it to back up into the vent.
Of course the vent is suppose to be closed except when it's drawing air in. But that's not the issue.
Your description doesn't totally describe the causes and symptoms. So are you saying in the absence of a few small solids the drain never slows down? Or are you saying it does that when the sink has a lot of water in it and it flows that large volume all at once?

In any case, I would suggest a couple of things.
1. Remove trap and snake drain line. That alone may be enough.???
2. Unscrew that vent fitting(AAV) and add a 90 degree Elbow to the left, then up, and put a new AAV as high up as you can while still making it accessible for replacement.

 

[CT18]

You may be able to just cut the AAV off and use a coupling to extend as high as possible like Diehard said. That AAV should be 6" above the flood level of the fixture it is serving for that exact reason. You may want to replace it also if it is letting water out, the spring is probably dead so it may be letting in sewer gases also.

 

[Diehard]

Yes, ideally the AAV should be above the rim of the sink so that it would never be possible for it flood out like that, but I don't think very many people have, nor want, that thing sticking up through their counter.
But the fact that it's not above the flood level is not the cause of your the problem.

 

[JewishBacon]

OK I'm going to go to home depot and get a new AAV, 2x 90 degree elbows and some 2" pvc. That will give me enough room to snake it over to where it's just below the counter and basically flush with the top of the sink. I run draino and boiling water down it all the time so I'm fairly sure there's no clog. That and the dishwasher drains fine. I think it just happens when there's a large volume of water rushing down at once.

 

[Diehard]

Be sure to let us know the outcome.

 

[JewishBacon]

Alright so far so good! Do I need to glue any of this?

 

[Diehard]

Alright so far so good! Do I need to glue any of this?

Glad to hear, "so far so good".
I've been dragging my feet waiting to hear what others have to say about your question. I would guess the experienced plumbers would say glue it.
I'd be inclined to glue at least the first rise up to the elbow.
Is there enough space to remove that AAV by unscrewing it? Looks pretty tight. That would be a reason to leave that closest elbow to the AAV unglued.

 

[Zanne]

Raising the vent up higher was a good idea, but generally a vent pipe should not run horizontal until it is 6" above the flood level rim. You can get away with having an AAV terminate below the flood level so long as it is at least 4" above the trap weir (but generally, you want to get it as high as possible, but also have the pipes as vertical as possible). When I was trying to figure out how to vent my sink I was told to use 45s instead of 90s to offest the vent slightly. First 45 would be right above where it comes out of the top and after diverting a bit over to the side, another 45 would make the pipe run straight up again just below the AAV. (I think it was 45s, might have been 1/8th bends but my memory is sucking today)

I'm not sure if having the 90s will be a problem or not though. Also, AAVs are generally designed for city sewer systems and sometimes the gases from a septic tank can blow the diaphragm in an AAV, so keep your nose open for sewer gas smell in case it does go.

Hopefully this will solve the problem though. The solvent weld parts (the ones that don't connect with the nut that twists on to hold them in place) need to be glued (but the AAV itself doesn't need to be glued, it can just thread in for easier replacement). If you haven't glued them already, you may be able to return the 90s and get 45s instead (or you can keep the 90s for future projects).

Diehard is right that you will need room to unscrew the AAV should it need to be replaced.

Disclaimer: I am not a plumber, but I've tried to learn what I can from the actual plumbers here. Frodo is the one who usually pipes in with the best answers (pun intended).

 

[JewishBacon]

There is room for the AAV to pop out and be replaced. I made sure of that by putting it in last.